4-YEARS RESULTS WITH 166HOLMIUM-PHYTATE TREATMENT OF CHRONIC SYNOVITIS

Background: 166-Holmium-phytate produced by us: radiation type beta energy maximum: 1.84 MeV; radiation type gamma energy maximum: 0.66 MeV; soft tissue penetration: maximum 8.4 mm; average: 3.3 mm; half-life: 26.9 hours; particle size: 0.6-2 μmObjectives: Examination of anti-inflammatory effect of 166-Holmium-phytate injection.Methods: Phases I-II, randomized, simple-blind, placebo-controlled comparative study using increasing dosage. 31 patients suffering from chronic synovitis, rheumatoid arthritis and seronegative spondylarthritis were examined.Patients: Gender (male/female): 12-19; Diagnosis (RA/SNSA): 21/10; Stage of knee joint x-ray (I/II): 7/24; Duration of synovitis (years): 7.9; Duration of disease (years): 5.72; Number of punctures before the Ho-166 treatment: 18.76; Number of steroid injections before the treatment: 18.85. The protocol commenced with screening. Patients were randomly distributed into four treatment arms: Group I. Holmium phytate injectable suspension marked by 185 MBq 166Ho + 40 mg of 1 ml triamcinolone acetonide (TA) + 1 ml of 1% lidocaine injection (Lid.inj). Group II. 555 MBq 166Ho. + 40 mg of 1 ml TA + 1 ml Lid.inj. Group III. 925 MBq 166Ho + 40 mg 1 ml TA + 1 ml of 1% Lid.inj. Group IV. Solely 40 mg of 1 ml TA + 1 ml of 1% Lid.inj. There were 48 month follow-up period after the administration of the isotope. The patients were selected according to inclusion and exclusion criteria. Inflammatory activity of the affected knee-joint was tested prior to treatment, and the 14th and 28th days, and 3, 6, 9, 12, 24, 36 and 48 months after treatment. Testing was done based on the following parameters: Measurement of swelling of knee-joint [cm]; Flexion – heal buttocks distance [cm]; Degree of knee-joint pain. Visual Analogue Scale (VAS-1-100); Patient's opinion on inflammation of knee-joint (VAS-1-100); Doctor's opinion on given inflammation of knee-joint (VAS-1-100).Results: Even after 4 year period 88.2% of the findings were rated as excellent or good. 86.66% of the patients do not need another punction even after a 4 years period. We found no deviations in either haematological or chemical parameters during the study period. Administration of Holmium-166 phytate is a safe procedure. We did not detect symptoms of radiation sickness. During the study period, inflammation decreased in the group receiving 555 and 925 MBq.Conclusion: Ho-166 isotope is an effective radiopharmacy treating synovitis. Due its adventageous features it produces less radioactive damage on the organism than the traditionally used isotopes (90-Yttrium, 169-Erbium, 186-Rhenium). Due to its physical parameters it is optimal to treat large joints (knee) and medium size joints (hips, shoulder, elbow, wrist, ankle). Effective dosage is 555-925 MBq.References: Koernyei J., Szentesi M., Foeldes I., Antalffy M., Toerko; J.: 166-Ho-IHPP the real alternative of 165-Dy-FHMA for radiosynovectomy. Eur.J.Nucl.Med.: 27: S96. 2000. Margit Szentesi: Radiosynoviorthesis with Ho-166 phytate. First clinical results. EANM Post-Congress Scintific Meeting. Radionuclide therapy in theory and practice. Gyor, Hungary. 5. sept. 2002.Citation: Ann Rheum Dis, volume 65, supplement II, year 2006, page 346Session: Rheumatic arthritis – treatment non-biologics